UVa 122 - Trees on the level

好久没出题了，脑子有点钝了。。。

 

#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<queue>
#include<vector>
using namespace std;

struct Node {
    int value;
    Node* Ltree;
    Node* Rtree;
};

Node* root;
bool failed;

Node* new_node() {
    return new Node();
}

void addnode(int v, char* s) {
    Node* u = root;
    int n = strlen(s);
    for(int i = 0; i < n; i++)
        if(s[i] == 'L') {
            if(u -> Ltree == NULL) u -> Ltree = new_node();
            u = u -> Ltree;
        } else if(s[i] == 'R') {
            if(u -> Rtree == NULL) u -> Rtree = new_node();
            u = u -> Rtree;
        }
    if(u -> value) failed = true;
    u -> value = v;
}

bool read_input() {
    failed = false;
    char cmd[10];
    root = new_node();
    for(;;) {
        if(scanf("%s", cmd) != 1) return false;
        if(!strcmp(cmd, "()")) break;
        int v;
        sscanf(cmd + 1, "%d", &v);
        addnode(v, strchr(cmd, ',') + 1);
    }
    return true;
}

bool bfs(vector<int>& ans) {
    ans.clear();
    queue<Node* > q;
    q.push(root);
    while(!q.empty()) {
        Node* u = q.front(); q.pop();
        if(!u -> value) return false;
        ans.push_back(u -> value);
        if(u -> Ltree != NULL) q.push(u -> Ltree);
        if(u -> Rtree != NULL) q.push(u -> Rtree);
    }
    return true;
}

void remove_node(Node* tree) {
    if(tree == NULL) return ;
    remove_node(tree -> Ltree);
    remove_node(tree -> Rtree);
    delete tree;
}

int main() {
    #ifndef ONLINE_JUDGE
        freopen("in.txt", "r", stdin);
    #endif // ONLINE_JUDGE
    while(read_input()) {
        vector<int> ans;
        if(bfs(ans)&& !failed)
            for(int i = 0; i < ans.size(); i++)
                i ? cout << " " << ans[i] : cout << ans[i];
        else cout << "not complete";
        cout << endl;
        remove_node(root);
    }
    return 0;
}